docstr: Prepare target by concatenating self if "env_corr" is used
docstr_tok: ["Prepare","target","by","concatenating","self","if","``","env_corr","''","is","used"]
code: def prepare_targets(self, tokens, stage):
      """Prepare target by concatenating self if "env_corr" is used"""
      tokens, token_lens = tokens
  
      if stage == sb.Stage.TRAIN and hasattr(
          self.hparams, "wav_augment"
      ):
          tokens = self.hparams.wav_augment.replicate_labels(tokens)
          token_lens = self.hparams.wav_augment.replicate_labels(
              token_lens
          )
  
      return tokens, token_lens
  
imports: import os
  import sys
  import torch
  import torchaudio
  import logging
  import speechbrain
  from pesq import pesq
  from pystoi import stoi
  from composite_eval import eval_composite
  from hyperpyyaml import load_hyperpyyaml
  from speechbrain.utils.data_utils import undo_padding
  from speechbrain.utils.distributed import run_on_main, if_main_process
label_desc: Use image node_id 4 for calling the MTLbrain obj's underlying member method code with example usage: obj.prepare_targets(tokens, stage) and returns: tokens,  token_lens